Comparison of estimation methods of soil strength in five soils

In agriculture, the soil strength is used to describe the susceptibility to deformation by pressure caused by agricultural machine. The purpose of this study was to compare different methods for estimating the inherent soil strength and to identify their suitability for the evaluation of load support capacity, compaction susceptibility and root growth. The physical, chemical, mineralogical and intrinsic strength properties of seven soil samples, collected from five sampling pits at different locations in Brazil, were measured. Four clay (CS) and three sandy clay loam (SCL) soils were used. The clay soils were collected on a farm in Santo Ângelo, RS (28 º 16 ' 16 '' S; 54 º 13 ' 11 '' W 290 m); A and B horizons at the Universidade Federal de Lavras, Lavras, MG (21 º 13 ' 47 '' S; 44 º 58 ' 6'' W; 918 m) and on the farm Sygenta, in Uberlandia, MG (18 º 58 ' 37 '' S; 48 º 12 ' 05 '' W 866 m). The sandy clay loam soils were collected in Aracruz, ES (19 º 47 ' 10 '' S; 40 º 16 ' 29 '' W 81 m), and on the farm Xavier, Lavras, MG (21 º 13 ' 24 '' S; 45 º 05 ' 00 '' W; 844 m). Soil strength was estimated based on measurements of: (a) a pneumatic consolidometer, (b) manual pocket (non-rotating) penetrometer; and (c) automatic (rotating) penetrometer. The results of soil strength properties were similar by the three methods. The soil structure had a significant influence on soil strength. Results of measurements with both the manual pocket and the electric penetrometer were similar, emphasizing the influence of soil texture. The data showed that, to enhance the reliability of predictions of preconsolidation pressure by penetrometers, it is better to separate the soils into the different classes, rather than analyze them jointly. It can be concluded that the consolidometer method, although expensive, is the best when evaluations of load support capacity and compaction susceptibility of soil samples are desired.

Root system distribution of sugar cane as related to nitrogen fertilization, evaluated by two methods: monolith and probes

Few studies on sugar cane have evaluated the root system of the crop, in spite of its importance. This is mainly due to the difficulty of evaluation and high variability of results. The objective of this study was to develop an evaluation method of the cane root system by means of probes so as to evaluate the mass, distribution and metabolically active roots related to N fertilization at planting. For this purpose, an experiment was conducted in an Arenic Kandiustults with medium texture in Jaboticabal/SP, in a randomized block design with four replications and four treatments: control (without N) and 40, 80 and 120 kg ha-1 of N applied in the form of urea in the planting furrow of the cane variety SP81 3250. One week before harvest, a urea-15N solution was applied at the cane stalk base to detect active metabolism in the root system. Trenches of 1.5 m length and 0.6 m depth were opened between two sugar cane rows for root sampling by two methods: monoliths (0.3, 0.2 and 0.15 m wide, deep and long respectively) taken from the trench wall and by probe (internal diameter 0.055 m). For each method, 15 samples per plot were collected. The roots were separated from the soil in a sieve (2 mm mesh), oven-dried (at 65 ºC) and the dry matter was measured. Root sampling by probes resulted in root mass that did not differ from the evaluation in monoliths, indicating that this evaluation method may be used for sugar cane root mass, although neither the root distribution in the soil profile nor the rhizome mass were efficiently evaluated, due to the small sample volume. Nitrogen fertilization at planting did not result in a greater root accumulation in the sugar cane plant, but caused changes in the distribution of the root system in the soil. The absence of N fertilization led to a better root distribution in the soil profile, with 50, 34 and 16 % in the 0-0.2, 0.2-0.4 and 0.4-0.6 m layers, respectively; in the fertilized treatments the roots were concentrated in the surface layer, with on average 70, 17 and 13 % for the same layers. The metabolically active roots were concentrated in the center of the cane stool, amounting to 40 % of the total root mass, regardless of N fertilization (application of 120 kg ha-1 N or without N).

In vitro evaluation of staphylococcus aureus biofilm formation on bone grafts and bone substitues

Background: Bacteria form a biofilm on the surface of orthopaedic devices, causing persistent and infection. Little is known about biofilms formation on bone grafts and bone substitutes. We analyzed various representative materials regarding their propensity for biofilm formation caused by Staphylococcus aureus.Methods: As bone graft beta-tricalciumphosphate (b-TCP, CyclOsTM) and as bone substitute a tantalum metal mesh (trabecular metalTM) and PMMA (Pala-cosTM) were investigated. As test organism S. aureus (strain ATCC 29213) was used. Test materials were incubated with bacterial solution of 105 colony-forming units (cfu)/ml at 37°C for 24 h without shaking. After 24 h, the test materials were removed and washed 3 times in normal saline, followed by sonication in 50 ml Ringer solution at 40 kHz for 5 minutes. The resulting sonication fluid was plated in aliquots of 0.1 ml onto aerobe blood agar with 5% sheep blood and incubated at 37°C with 5% CO2 for 24 h. Then, bacterial counts were enumerated and expressed as cfu/ml. All experiments were performed in triplicate to calculate the mean ± standard deviation. The Wilcoxon test was used for statistical calculations.Results: The three investigated materials show a differing specific surface with b-TCB>trabecular metal>PMMA per mm2. S. aureus formed biofilm on all test materials as confirmed by quantitative culture after washing and sonication. The bacterial counts in sonication fluid (in cfu/ml) were higher in b-TCP (5.1 x 106 ± 0.6 x 106) and trabecular metal (3.7 x 106 ± 0.6 x 106) than in PMMA (3.9 x 104 ± 1.8 x 104), p<0.05.Conclusion: Our results demonstrate that about 100-times more bacteria adhere on b-TCP and trabecular metal than on PMMA, reflecting the larger surface of b-TCP and trabecuar metal compared to the one of PMMA. This in-vitro data indicates that bone grafts are susceptible to infection. Further studies are needed to evaluate efficient approaches to prevent and treat infections associated with bone grafts and substitutes, including modification of the surface or antibacterial coating.

Pseudoxanthoma elasticum : evaluation of diagnostic criteria based on molecular data

RÉSUMÉ EN FRANCAIS : Introduction: Le pseudoxanthome élastique (PXE) est une maladie génétique. Les mutations responsables ont été localisées au niveau du gène codant le transporteur transmembranaire ABC-C6. Des calcifications pathologiques des fibres élastiques de la peau, des yeux et du système cardiovasculaire en sont la conséquence. Buts: Evaluer les critères diagnostiques actuels du PXE en se basant sur les données moléculaires. Méthodes: 142 sujets provenant de 10 familles avec une anamnèse familiale positive pour le PXE ont été investiguées sur le plan clinique, histopathologique et génétique. Résultats: 25 sujets se sont avérés être homozygotes pour le gène PXE muté. 23 d'entre eux ont présenté les manifestations cliniques et histopathologique typiques. Les deux autres souffraient d'une élastose et d'une dégénérescence maculaire si importante qu'un diagnostic de PXE ne pouvait pas être confirmé cliniquement. 67 sujets se sont révélés être des porteurs hétérozygotes et 50 ne présentaient pas de mutation. De ces 117 sujets, 116 n'ont montré aucune lésion cutanée ou ophtalmique pouvant correspondre au PXE. Un seul des sujets sans mutation a présenté une importante élastose solaire ainsi qu'une cicatrisation de la rétine, imitant les lésions typiques du PXE. Quatre des 67 sujets hétérozygotes ont eu une biopsie de peau, dont les analyses histopathologique se sont avérées normales. Conclusion: Dans notre cohorte de patients, le PXE était transmis exclusivement de façoh autosomique récessive. La corrélation retrouvée entre le génotype et le phénotype a permis de confirmer les critères diagnostiques majeurs actuels. Le diagnostic clinique peut être difficile, voir impossible, chez des patients atteints d'une élastose solaire importante et/ou d'une dégénérescence maculaire étendue. Dans ces cas, un test moléculaire est nécessaire afin de confirmer le diagnostic de PXE. A notre connaissance, notre étude présentée ici est le premier travail comparant des données cliniques à des données moléculaires dans le domaine du PXE. ABSTRACT : Background: Pseudoxanthoma elasticum (PXE) is a genetic disorder due to mutations in the gene encoding the transmembrane transporter protein adenosine triphosphate binding cassette (ABC)-C6, resulting in calcifications of elastic fibers in the skin, eyes and cardiovascular system. Objectives: To evaluate the diagnostic criteria for PXE based on molecular data. Methods: Of 10 families with a positive history of PXE 142 subjects were investigated for clinical symptoms, histological findings and genetic haplotype analysis. Results: Of these, 25 subjects were haplotypic homozygous for PXE and 23 had typical clinical and histopathological manifestations. Two of the 25 patients showed such marked solar elastosis and macular degeneration that PXE could not be confirmed clinically. Sixty-seven subject were haplotypic heterozygous carriers and 50 haplotypic homozygous unaffected. Of these 117 subjects, 116 showed no cutaneous or ophthalmologic signs of PXE. In one of the 50 haplotypic homozygous unaffected patients important solar elastosis and scaring of the retina mimicked PXE lesions. Only four of the 67 haplotypic heterozygous carriers had biopsies of nonlesional skin; all were histopathologically normal. Conclusions: In our patients, PXE presents as an autosomal recessive genodermatosis. Correlation of haplotype and phenotype confirmed actual major diagnostic criteria. In patients with marked solar elastosis and/ or severe macular degeneration clinical diagnosis can be impossible and molecular testing is needed to confirm the presence of PXE. To the best of our knowledge our large study compares for the first time clinical findings with molecular data.

Critical evaluation of outcome scales assessment of lateral ankle ligament reconstruction.

BACKGROUND: Outcome following foot and ankle surgery can be assessed by disease- and region-specific scores. Many scoring systems exist, making comparison among studies difficult. The present study focused on outcome measures for a common foot and ankle abnormality and compared the results obtained by 2 disease-specific and 2 body region-specific scores. METHODS: We reviewed 41 patients who underwent lateral ankle ligament reconstruction. Four outcome scales were administered simultaneously: the Cumberland Ankle Instability Tool (CAIT) and the Chronic Ankle Instability Scale (CAIS), which are disease specific, and the American Orthopedic Foot & Ankle Society (AOFAS) hindfoot scale and the Foot and Ankle Ability Measure (FAAM), which are both body region-specific. The degree of correlation between scores was assessed by Pearson's correlation coefficient. Nonparametric tests, the Kruskal-Wallis and the Mann-Whitney test for pairwise comparison of the scores, were performed. RESULTS: A significant difference (P < .005) was observed between the CAIS and the AOFAS score (P = .0002), between the CAIS and the FAAM 1 (P = .0001), and between the CAIT and the AOFAS score (P = .0003). CONCLUSIONS: This study compared the performances of 4 disease- and body region-specific scoring systems. We demonstrated a correlation between the 4 administered scoring systems and notable differences between the results given by each of them. Disease-specific scores appeared more accurate than body region-specific scores. A strong correlation between the AOFAS score and the other scales was observed. The FAAM seemed a good compromise because it offered the possibility to evaluate the patient according to his or her own functional demand. CLINICAL RELEVANCE: The present study contributes to the development of more critical and accurate outcome assesment methods in foot and ankle surgery.

New methods to quantify NH3 volatilization from fertilized surface soil with urea

Gaseous N losses from soil are considerable, resulting mostly from ammonia volatilization linked to agricultural activities such as pasture fertilization. The use of simple and accessible measurement methods of such losses is fundamental in the evaluation of the N cycle in agricultural systems. The purpose of this study was to evaluate quantification methods of NH3 volatilization from fertilized surface soil with urea, with minimal influence on the volatilization processes. The greenhouse experiment was arranged in a completely randomized design with 13 treatments and five replications, with the following treatments: (1) Polyurethane foam (density 20 kg m-3) with phosphoric acid solution absorber (foam absorber), installed 1, 5, 10 and 20 cm above the soil surface; (2) Paper filter with sulfuric acid solution absorber (paper absorber, 1, 5, 10 and 20 cm above the soil surface); (3) Sulfuric acid solution absorber (1, 5 and 10 cm above the soil surface); (4) Semi-open static collector; (5) 15N balance (control). The foam absorber placed 1 cm above the soil surface estimated the real daily rate of loss and accumulated loss of NH3N and proved efficient in capturing NH3 volatized from urea-treated soil. The estimates based on acid absorbers 1, 5 and 10 cm above the soil surface and paper absorbers 1 and 5 cm above the soil surface were only realistic for accumulated N-NH3 losses. Foam absorbers can be indicated to quantify accumulated and daily rates of NH3 volatilization losses similarly to an open static chamber, making calibration equations or correction factors unnecessary.

Evaluation of risk perception related to drug use during pregnancy: a Swiss survey

Introduction Health care professionals' perception of risk mayimpact on therapeutic management of women during pregnancy.Since the thalidomide tragedy, the use of drugs during pregnancygenerates fear. This concern might affect the estimation of the riskassociated with drug intake during pregnancy, leading to prematurediscontinuation of a required treatment, superfluous anxiety orpointless termination of a desired pregnancy. Although data regardingthe security of drugs during pregnancy are still scarce, a few specializedinformation sources exist providing reliable recommendationsfor daily practice. This study aimed at characterizing therisk perception associated with drugs during pregnancy in a sample ofSwiss health care professionals.Materials & Methods An online French and German survey was sentby email to the Swiss professional societies of Pharmacists, Gynecologists,Mid-wives and Pediatricians. The questionnaire wasconstructed to assess (a) the characteristics of the population and theopinion of the professionals regarding the medication use pattern intheir pregnant patients, (b) to evaluate the sources of information usedduring their practice and finally (c) to assess their risk perceptionassociated with drugs during pregnancy. Results were analyzed bydescriptive statistics.Results A total of 1,310 questionnaires were collected (18% responserate). Most health care professionals believe that 30-60% of theirpregnant patients are taking at least one treatment during their pregnancyand that 80% are adherent to it. A large majority think,however, that women are anxious when they must take their medication.More than 80% of health professionals commonly use theSwiss Drug Reference Book (Compendium) to assess the risk associatedwith drugs during pregnancy, despite the uniformly low levelof credibility and utility they express about this reference. Except forsome gynecologists, the majority of professionals are not aware of ordo not use specialized books. The majority of participants thinkwrongly that more than 30% of drugs are teratogenic. About 20% ofthem are not aware of the risk associated with paracetamol intakeduring pregnancy. More than 70% agree that phytotherapeutic mixturesare not safer than conventional drugs, with the exception of midwiveswho tend to overestimate the safety of such drugs. With thenotable exception of gynecologists, the risk related to drug intake wasoverall overestimated.Discussion & Conclusion Swiss professionals differ in their perceptionof the risk associated with drugs during pregnancy and tend tooverestimate it. The differences might be attributed to the level oftraining and awareness of specialized sources offering a realisticestimation of the risk. Further efforts are needed to expand thetraining and the tools for health care professionals to optimize druguse during pregnancy.

Assessment of the occurrence of nanoparticles in Swiss industry and evaluation of the appropriatenesss of the measurement devices to determine the workforce exposure

Abstract : The occupational health risk involved with handling nanoparticles is the probability that a worker will experience an adverse health effect: this is calculated as a function of the worker's exposure relative to the potential biological hazard of the material. Addressing the risks of nanoparticles requires therefore knowledge on occupational exposure and the release of nanoparticles into the environment as well as toxicological data. However, information on exposure is currently not systematically collected; therefore this risk assessment lacks quantitative data. This thesis aimed at, first creating the fundamental data necessary for a quantitative assessment and, second, evaluating methods to measure the occupational nanoparticle exposure. The first goal was to determine what is being used where in Swiss industries. This was followed by an evaluation of the adequacy of existing measurement methods to assess workplace nanopaiticle exposure to complex size distributions and concentration gradients. The study was conceived as a series of methodological evaluations aimed at better understanding nanoparticle measurement devices and methods. lt focused on inhalation exposure to airborne particles, as respiration is considered to be the most important entrance pathway for nanoparticles in the body in terms of risk. The targeted survey (pilot study) was conducted as a feasibility study for a later nationwide survey on the handling of nanoparticles and the applications of specific protection means in industry. The study consisted of targeted phone interviews with health and safety officers of Swiss companies that were believed to use or produce nanoparticles. This was followed by a representative survey on the level of nanoparticle usage in Switzerland. lt was designed based on the results of the pilot study. The study was conducted among a representative selection of clients of the Swiss National Accident Insurance Fund (SUVA), covering about 85% of Swiss production companies. The third part of this thesis focused on the methods to measure nanoparticles. Several pre- studies were conducted studying the limits of commonly used measurement devices in the presence of nanoparticle agglomerates, This focus was chosen, because several discussions with users and producers of the measurement devices raised questions about their accuracy measuring nanoparticle agglomerates and because, at the same time, the two survey studies revealed that such powders are frequently used in industry. The first preparatory experiment focused on the accuracy of the scanning mobility particle sizer (SMPS), which showed an improbable size distribution when measuring powders of nanoparticle agglomerates. Furthermore, the thesis includes a series of smaller experiments that took a closer look at problems encountered with other measurement devices in the presence of nanoparticle agglomerates: condensation particle counters (CPC), portable aerosol spectrometer (PAS) a device to estimate the aerodynamic diameter, as well as diffusion size classifiers. Some initial feasibility tests for the efficiency of filter based sampling and subsequent counting of carbon nanotubes (CNT) were conducted last. The pilot study provided a detailed picture of the types and amounts of nanoparticles used and the knowledge of the health and safety experts in the companies. Considerable maximal quantities (> l'000 kg/year per company) of Ag, Al-Ox, Fe-Ox, SiO2, TiO2, and ZnO (mainly first generation particles) were declared by the contacted Swiss companies, The median quantity of handled nanoparticles, however, was 100 kg/year. The representative survey was conducted by contacting by post mail a representative selection of l '626 SUVA-clients (Swiss Accident Insurance Fund). It allowed estimation of the number of companies and workers dealing with nanoparticles in Switzerland. The extrapolation from the surveyed companies to all companies of the Swiss production sector suggested that l'309 workers (95%-confidence interval l'073 to l'545) of the Swiss production sector are potentially exposed to nanoparticles in 586 companies (145 to l'027). These numbers correspond to 0.08% (0.06% to 0.09%) of all workers and to 0.6% (0.2% to 1.1%) of companies in the Swiss production sector. To measure airborne concentrations of sub micrometre-sized particles, a few well known methods exist. However, it was unclear how well the different instruments perform in the presence of the often quite large agglomerates of nanostructured materials. The evaluation of devices and methods focused on nanoparticle agglomerate powders. lt allowed the identification of the following potential sources of inaccurate measurements at workplaces with considerable high concentrations of airborne agglomerates: - A standard SMPS showed bi-modal particle size distributions when measuring large nanoparticle agglomerates. - Differences in the range of a factor of a thousand were shown between diffusion size classifiers and CPC/SMPS. - The comparison between CPC/SMPS and portable aerosol Spectrometer (PAS) was much better, but depending on the concentration, size or type of the powders measured, the differences were still of a high order of magnitude - Specific difficulties and uncertainties in the assessment of workplaces were identified: the background particles can interact with particles created by a process, which make the handling of background concentration difficult. - Electric motors produce high numbers of nanoparticles and confound the measurement of the process-related exposure. Conclusion: The surveys showed that nanoparticles applications exist in many industrial sectors in Switzerland and that some companies already use high quantities of them. The representative survey demonstrated a low prevalence of nanoparticle usage in most branches of the Swiss industry and led to the conclusion that the introduction of applications using nanoparticles (especially outside industrial chemistry) is only beginning. Even though the number of potentially exposed workers was reportedly rather small, it nevertheless underscores the need for exposure assessments. Understanding exposure and how to measure it correctly is very important because the potential health effects of nanornaterials are not yet fully understood. The evaluation showed that many devices and methods of measuring nanoparticles need to be validated for nanoparticles agglomerates before large exposure assessment studies can begin. Zusammenfassung : Das Gesundheitsrisiko von Nanopartikel am Arbeitsplatz ist die Wahrscheinlichkeit dass ein Arbeitnehmer einen möglichen Gesundheitsschaden erleidet wenn er diesem Stoff ausgesetzt ist: sie wird gewöhnlich als Produkt von Schaden mal Exposition gerechnet. Für eine gründliche Abklärung möglicher Risiken von Nanomaterialien müssen also auf der einen Seite Informationen über die Freisetzung von solchen Materialien in die Umwelt vorhanden sein und auf der anderen Seite solche über die Exposition von Arbeitnehmenden. Viele dieser Informationen werden heute noch nicht systematisch gesarnmelt und felilen daher für Risikoanalysen, Die Doktorarbeit hatte als Ziel, die Grundlagen zu schaffen für eine quantitative Schatzung der Exposition gegenüber Nanopartikel am Arbeitsplatz und die Methoden zu evaluieren die zur Messung einer solchen Exposition nötig sind. Die Studie sollte untersuchen, in welchem Ausmass Nanopartikel bereits in der Schweizer Industrie eingesetzt werden, wie viele Arbeitnehrner damit potentiel] in Kontakt komrrien ob die Messtechnologie für die nötigen Arbeitsplatzbelastungsmessungen bereits genügt, Die Studie folcussierte dabei auf Exposition gegenüber luftgetragenen Partikel, weil die Atmung als Haupteintrittspforte iïlr Partikel in den Körper angesehen wird. Die Doktorarbeit besteht baut auf drei Phasen auf eine qualitative Umfrage (Pilotstudie), eine repräsentative, schweizerische Umfrage und mehrere technische Stndien welche dem spezitischen Verständnis der Mëglichkeiten und Grenzen einzelner Messgeräte und - teclmikeri dienen. Die qualitative Telephonumfrage wurde durchgeführt als Vorstudie zu einer nationalen und repräsentativen Umfrage in der Schweizer Industrie. Sie zielte auf Informationen ab zum Vorkommen von Nanopartikeln, und den angewendeten Schutzmassnahmen. Die Studie bestand aus gezielten Telefoninterviews mit Arbeit- und Gesundheitsfachpersonen von Schweizer Unternehmen. Die Untemehmen wurden aufgrund von offentlich zugànglichen lnformationen ausgewählt die darauf hinwiesen, dass sie mit Nanopartikeln umgehen. Der zweite Teil der Dolctorarbeit war die repräsentative Studie zur Evalniernng der Verbreitnng von Nanopaitikelanwendungen in der Schweizer lndustrie. Die Studie baute auf lnformationen der Pilotstudie auf und wurde mit einer repräsentativen Selektion von Firmen der Schweizerischen Unfall Versicherungsanstalt (SUVA) durchgeüihxt. Die Mehrheit der Schweizerischen Unternehmen im lndustrieselctor wurde damit abgedeckt. Der dritte Teil der Doktorarbeit fokussierte auf die Methodik zur Messung von Nanopartikeln. Mehrere Vorstudien wurden dnrchgefîihrt, um die Grenzen von oft eingesetzten Nanopartikelmessgeräten auszuloten, wenn sie grösseren Mengen von Nanopartikel Agglomeraten ausgesetzt messen sollen. Dieser F okns wurde ans zwei Gründen gewählt: weil mehrere Dislcussionen rnit Anwendem und auch dem Produzent der Messgeràte dort eine Schwachstelle vermuten liessen, welche Zweifel an der Genauigkeit der Messgeräte aufkommen liessen und weil in den zwei Umfragestudien ein häufiges Vorkommen von solchen Nanopartikel-Agglomeraten aufgezeigt wurde. i Als erstes widmete sich eine Vorstndie der Genauigkeit des Scanning Mobility Particle Sizer (SMPS). Dieses Messgerät zeigte in Präsenz von Nanopartikel Agglorneraten unsinnige bimodale Partikelgrössenverteilung an. Eine Serie von kurzen Experimenten folgte, welche sich auf andere Messgeräte und deren Probleme beim Messen von Nanopartikel-Agglomeraten konzentrierten. Der Condensation Particle Counter (CPC), der portable aerosol spectrometer (PAS), ein Gerät zur Schàtzung des aerodynamischen Durchniessers von Teilchen, sowie der Diffusion Size Classifier wurden getestet. Einige erste Machbarkeitstests zur Ermittlnng der Effizienz von tilterbasierter Messung von luftgetragenen Carbon Nanotubes (CNT) wnrden als letztes durchgeiührt. Die Pilotstudie hat ein detailliiertes Bild der Typen und Mengen von genutzten Nanopartikel in Schweizer Unternehmen geliefert, und hat den Stand des Wissens der interviewten Gesundheitsschntz und Sicherheitsfachleute aufgezeigt. Folgende Typen von Nanopaitikeln wurden von den kontaktierten Firmen als Maximalmengen angegeben (> 1'000 kg pro Jahr / Unternehrnen): Ag, Al-Ox, Fe-Ox, SiO2, TiO2, und ZnO (hauptsächlich Nanopartikel der ersten Generation). Die Quantitäten von eingesetzten Nanopartikeln waren stark verschieden mit einem ein Median von 100 kg pro Jahr. ln der quantitativen Fragebogenstudie wurden l'626 Unternehmen brieflich kontaktiert; allesamt Klienten der Schweizerischen Unfallversicherringsanstalt (SUVA). Die Resultate der Umfrage erlaubten eine Abschätzung der Anzahl von Unternehmen und Arbeiter, welche Nanopartikel in der Schweiz anwenden. Die Hochrechnung auf den Schweizer lndnstriesektor hat folgendes Bild ergeben: ln 586 Unternehmen (95% Vertrauensintervallz 145 bis 1'027 Unternehmen) sind 1'309 Arbeiter potentiell gegenüber Nanopartikel exponiert (95%-Vl: l'073 bis l'545). Diese Zahlen stehen für 0.6% der Schweizer Unternehmen (95%-Vl: 0.2% bis 1.1%) und 0.08% der Arbeiternehmerschaft (95%-V1: 0.06% bis 0.09%). Es gibt einige gut etablierte Technologien um die Luftkonzentration von Submikrometerpartikel zu messen. Es besteht jedoch Zweifel daran, inwiefern sich diese Technologien auch für die Messurrg von künstlich hergestellten Nanopartikeln verwenden lassen. Aus diesem Grund folcussierten die vorbereitenden Studien für die Arbeitsplatzbeurteilnngen auf die Messung von Pulverri, welche Nan0partike1-Agg10merate enthalten. Sie erlaubten die ldentifikation folgender rnöglicher Quellen von fehlerhaften Messungen an Arbeitsplätzen mit erhöhter Luft-K0nzentrati0n von Nanopartikel Agglomeratenz - Ein Standard SMPS zeigte eine unglaubwürdige bimodale Partikelgrössenverteilung wenn er grössere Nan0par'til<e1Agg10merate gemessen hat. - Grosse Unterschiede im Bereich von Faktor tausend wurden festgestellt zwischen einem Diffusion Size Classiîier und einigen CPC (beziehungsweise dem SMPS). - Die Unterschiede zwischen CPC/SMPS und dem PAS waren geringer, aber abhängig von Grosse oder Typ des gemessenen Pulvers waren sie dennoch in der Grössenordnung von einer guten Grössenordnung. - Spezifische Schwierigkeiten und Unsicherheiten im Bereich von Arbeitsplatzmessungen wurden identitiziert: Hintergrundpartikel können mit Partikeln interagieren die während einem Arbeitsprozess freigesetzt werden. Solche Interaktionen erschweren eine korrekte Einbettung der Hintergrunds-Partikel-Konzentration in die Messdaten. - Elektromotoren produzieren grosse Mengen von Nanopartikeln und können so die Messung der prozessbezogenen Exposition stören. Fazit: Die Umfragen zeigten, dass Nanopartikel bereits Realitàt sind in der Schweizer Industrie und dass einige Unternehmen bereits grosse Mengen davon einsetzen. Die repräsentative Umfrage hat diese explosive Nachricht jedoch etwas moderiert, indem sie aufgezeigt hat, dass die Zahl der Unternehmen in der gesamtschweizerischen Industrie relativ gering ist. In den meisten Branchen (vor allem ausserhalb der Chemischen Industrie) wurden wenig oder keine Anwendungen gefunden, was schliessen last, dass die Einführung dieser neuen Technologie erst am Anfang einer Entwicklung steht. Auch wenn die Zahl der potentiell exponierten Arbeiter immer noch relativ gering ist, so unterstreicht die Studie dennoch die Notwendigkeit von Expositionsmessungen an diesen Arbeitsplätzen. Kenntnisse um die Exposition und das Wissen, wie solche Exposition korrekt zu messen, sind sehr wichtig, vor allem weil die möglichen Auswirkungen auf die Gesundheit noch nicht völlig verstanden sind. Die Evaluation einiger Geräte und Methoden zeigte jedoch, dass hier noch Nachholbedarf herrscht. Bevor grössere Mess-Studien durgefîihrt werden können, müssen die Geräte und Methodem für den Einsatz mit Nanopartikel-Agglomeraten validiert werden.

Stress ulcer prophylaxis in non-critically ill patients: a prospective evaluation of current practice in a general surgery department

Objective: There is little evidence regarding the benefit of stress ulcer prophylaxis (SUP) outside critical care setting. Over-prescription of SUP is not devoid of risks. This prospective study aimed to evaluate the use of proton pump inhibitors (PPIs) for SUP in a general surgery department.Methods: Data collection was performed prospectively during an 8-week period on patients hospitalized in a general surgery department (58 beds) by pharmacists. Patients with a PPI prescription for the treatment of ulcers, gastro-oesophageal reflux disease, oesophagitis or epigastric pain were excluded. Patients admitted twice during the study period were not re-included. The American Society of Health-System Pharmacists guidelines on SUP were used to assess the appropriateness of de novo PPI prescriptions.Results: Among 255 consecutive patients in the study, 138 (54%) received a prophylaxis with PPI, of which 86 (62%) were de novo PPI prescriptions. One-hundred twenty-nine patients (94%) received esomeprazole (according to the hospital drug policy). The most frequent dosage was 40 mg/day. Use of PPI for SUP was evaluated in 67 patients. Fifty-three patients (79%) had no risk factors for SUP. Twelve and 2 patients had one or two risk factors, respectively. At discharge, PPI prophylaxis was continued in 34% of patients with a de novo PPI prescription.Conclusion: This study highlights the overuse of PPIs in non-ICU patients and the inappropriate continuation of PPI prescriptions at discharge.Treatment

Outcome evaluation of ankle osteoarthritis treatments: plantar pressure analysis during relatively long-distance walking.

Background : This study aimed to use plantar pressure analysis in relatively long-distance walking for objective outcome evaluation of ankle osteoarthritis treatments, i.e., ankle arthrodesis and total ankle replacement.Methods : Forty-seven subjects in four groups: three patient groups and controls, participated in the study. Each subject walked twice in 50-m trials. Plantar pressure under the pathological foot was measured using pressure insoles. Six parameters: initial contact time, terminal contact time, maximum force time, peak pressure time, maximum force and peak pressure were calculated and averaged over trials in ten regions of foot. The parameters in each region were compared between patient groups and controls and their effect size was estimated. Besides, the correlations between pressure parameters and clinical scales were calculated.Findings : We observed based on temporal parameters that patients postpone the heel-off event, when high force in forefoot and high ankle moment happens. Also based on maximum force and peak pressure, the patients apply smoothened maximum forces on the affected foot. In ten regions, some parameters showed improvements after total ankle replacement, some showed alteration of foot function after ankle arthrodesis and some others showed still abnormality after both surgical treatments. These parameters showed also significant correlation with clinical scales in at least two regions of foot.Interpretation : Plantar pressure parameters in relatively long-distance trials showed to be strong tools for outcome evaluation of ankle osteoarthritis treatments. (C) 2010 Elsevier Ltd. All rights reserved.

HR-243 Production and Evaluation of Calcium Magnesium Acetate, Febrauray 19, 2001

Calcium magnesium acetate (CMA) has been identified by Bjorksten Research Laboratories as an environmentally harmless alternative to sodium or calcium chloride for deicing highways. Their study found CMA to be noncorrosive to steel, aluminum and zinc with little or no anticipated environmental impact. When used, it degrades into elements found in abundance in nature. The deicing capabilities were found to be similar to sodium chloride. The neutralized CMA they produced did cause scaling of PC concrete, but they did not expect mildly alkaline CMA to have this effect. In the initial investigation of CMA at the Iowa DOT laboratory, it was found that CMA produced from hydrated lime and acetic acid was a light, fluffy material. It was recognized that a deicer in this form would be difficult to effectively distribute on highways without considerable wind loss. A process was developed to produce CMA in the presence of sand to increase particle weight. In this report the product of this process, which consists of sand particles coated with CMA, is referred to as "CMA deicer". The mixture of salts, calcium magnesium acetate, is referred to as "CMA". The major problems with CMA for deicing are: (1) it is not commercially available, (2) it is expensive with present production methods and (3) there is very little known about how it performs on highways under actual deicing conditions. In view of the potential benefits this material offers, it is highly desirable to find solutions or answers to these problems. This study provides information to advance that effort.

Comprehensive Bridge Deck Deterioration Mapping of Nine Bridges by Nondestructive Evaluation Technologies Final Report, January 2011

The primary objective of this research was to demonstrate the benefits of NDT technologies for effectively detecting and characterizing deterioration in bridge decks. In particular, the objectives were to demonstrate the capabilities of ground-penetrating radar (GPR) and impact echo (IE), and to evaluate and describe the condition of nine bridge decks proposed by Iowa DOT. The first part of the report provides a detailed review of the most important deterioration processes in concrete decks, followed by a discussion of the five NDT technologies utilized in this project. In addition to GPR and IE methods, three other technologies were utilized, namely: half-cell (HC) potential, electrical resistivity (ER), and ultrasonic surface waves (USW) method. The review includes a description of the principles of operation, field implementation, data analysis, and interpretation; information regarding their advantages and limitations in bridge deck evaluations and condition monitoring are also implicitly provided.. The second part of the report provides descriptions and bridge deck evaluation results from the nine bridges. The results of the NDT surveys are described in terms of condition assessment maps and are compared with the observations obtained from the recovered cores or conducted bridge deck rehabilitation. Results from this study confirm that the used technologies can provide detailed and accurate information about a certain type of deterioration, electrochemical environment, or defect. However, they also show that a comprehensive condition assessment of bridge decks can be achieved only through a complementary use of multiple technologies at this stage,. Recommendations are provided for the optimum implementation of NDT technologies for the condition assessment and monitoring of bridge decks.

CO2 wedged hepatic venography in the evaluation of portal hypertension.

BACKGROUND/AIMS/METHODS During hepatic vein catheterisation, in addition to measurement of hepatic venous pressure gradient (HVPG), iodine wedged retrograde portography can be easily obtained. However, it rarely allows correct visualisation of the portal vein. Recently, CO2 has been suggested to allow better angiographic demonstration of the portal vein than iodine. In this study we investigated the efficacy of CO2 compared with iodinated contrast medium for portal vein imaging and its role in the evaluation of portal hypertension in a series of 100 patients undergoing hepatic vein catheterisation, 71 of whom had liver cirrhosis. RESULTS In the overall series, CO2 venography was markedly superior to iodine, allowing correct visualisation of the different segments of the portal venous system. In addition, CO2, but not iodine, visualised portal-systemic collaterals in 34 patients. In cirrhosis, non-visualisation of the portal vein on CO2 venography occurred in 11 cases; four had portal vein thrombosis and five had communications between different hepatic veins. Among non-cirrhotics, lack of portal vein visualisation had a 90% sensitivity, 88% specificity, 94% negative predictive value, and 83% positive predictive value in the diagnosis of pre-sinusoidal portal hypertension. CONCLUSIONS Visualisation of the venous portal system by CO2 venography is markedly superior to iodine. The use of CO2 wedged portography is a useful and safe complementary procedure during hepatic vein catheterisation which may help to detect portal thrombosis. Also, lack of demonstration of the portal vein in non-cirrhotic patients strongly suggests the presence of pre-sinusoidal portal hypertension.

Outpatient Quick Diagnosis Units for the evaluation of suspected severe diseases: an observational, descriptive study

Background: Hospitals in countries with public health systems have recently adopted organizational changes to improve efficiency and resource allocation, and reducing inappropriate hospitalizations has been established as an important goal. AIMS: Our goal was to describe the functioning of a Quick Diagnosis Unit in a Spanish public university hospital after evaluating 1,000 consecutive patients. We also aimed to ascertain the degree of satisfaction among Quick Diagnosis Unit patients and the costs of the model compared to conventional hospitalization practices. DESIGN: Observational, descriptive study. METHODS: Our sample comprised 1,000 patients evaluated between November 2008 and January 2010 in the Quick Diagnosis Unit of a tertiary university public hospital in Barcelona. Included patients were those who had potentially severe diseases and would normally require hospital admission for diagnosis but whose general condition allowed outpatient treatment. We analyzed several variables, including time to diagnosis, final diagnoses and hospitalizations avoided, and we also investigated the mean cost (as compared to conventional hospitalization) and the patients' satisfaction. RESULTS: In 88% of cases, the reasons for consultation were anemia, anorexia-cachexia syndrome, febrile syndrome, adenopathies, abdominal pain, chronic diarrhea and lung abnormalities. The most frequent diagnoses were cancer (18.8%; mainly colon cancer and lymphoma) and Iron-deficiency anemia (18%). The mean time to diagnosis was 9.2 days (range 1 to 19 days). An estimated 12.5 admissions/day in a one-year period (in the internal medicine department) were avoided. In a subgroup analysis, the mean cost per process (admission-discharge) for a conventional hospitalization was 3,416.13 Euros, while it was 735.65 Euros in the Quick Diagnosis Unit. Patients expressed a high degree of satisfaction with Quick Diagnosis Unit care. CONCLUSIONS: Quick Diagnosis Units represent a useful and cost-saving model for the diagnostic study of patients with potentially severe diseases. Future randomized study designs involving comparisons between controls and intervention groups would help elucidate the usefulness of Quick Diagnosis Units as an alternative to conventional hospitalization.

Evaluation of uptake and transport of ultrasmall superparamagnetic iron oxide nanoparticles by human brain-derived endothelial cells.

Aim: Ultrasmall superparamagnetic iron oxide nanoparticles (USPIO-NPs) are under development for imaging and drug delivery; however, their interaction with human blood-brain barrier models is not known. Materials & Methods: The uptake, reactive oxygen species production and transport of USPIO-NPs across human brain-derived endothelial cells as models of the blood-brain tumor barrier were evaluated for either uncoated, oleic acid-coated or polyvinylamine-coated USPIO-NPs. Results: Reactive oxygen species production was observed for oleic acid-coated and polyvinylamine-coated USPIO-NPs. The uptake and intracellular localization of the iron oxide core of the USPIO-NPs was confirmed by transmission electron microscopy. However, while the uptake of these USPIO-NPs by cells was observed, they were neither released by nor transported across these cells even in the presence of an external dynamic magnetic field. Conclusion: USPIO-NP-loaded filopodia were observed to invade the polyester membrane, suggesting that they can be transported by migrating angiogenic brain-derived endothelial cells.